Premium
Structural and functional changes associated with heat‐induced phase‐separations of non‐bilayer lipids in chloroplast thylakoid membranes
Author(s) -
Gounaris Kleoniki,
Brain Anthony P.R.,
Quinn Peter J.,
Williams W.Patrick
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80117-3
Subject(s) - thylakoid , photosystem , membrane , bilayer , chloroplast , biophysics , chloroplast membrane , membrane structure , chemistry , lipid bilayer , biochemistry , biology , gene
The effect of hearing isolated bean chloroplasts on the structure of their thylakoid membranes has been examined by freeze‐fracture electron microscopy. A normal morphology of the membranes in which stacked grana can be observed is preserved up to 35°C. Incubation at 35–45°C causes complete destacking of the grana but no alteration in the distribution of the membrane‐associated particles between the exoplasmic and protoplasmic fracture faces. Heating above 45°C causes phase‐separation of non‐bilayer lipids into aggregates of cylindrical inverted micelles. Bleaching experiments show that destacking is associated with disruption of chlorophyll‐protein complexes of both photosystems I and II. The rate of electron transport through the photosystems is also perturbed. These results are discussed in terms of the role of non‐bilayer lipids in packaging the membrane proteins.